Resolved Question:

This P0506 code is one that's sometimes triggered on vehicles that have electronic throttle control. That is, they don't have a regular throttle cable from the accelerator pedal to the engine. They rely on sensors and electronics to control the throttle. In this case, the P0506 DTC (diagnostic trouble code) is triggered when the PCM (powertrain control module) detects an engine idle speed that is lower than the desired (pre-programmed) RPM.

P0506 DTC trouble code may be caused by one or more of the following:

A vacuum leak

An air restriction in the intake air path or exhuast

A faulty positive crankcase ventilation (PCV) valve

Damaged/failed/dirty throttle body

Internal engine problem

Failed PCM

This DTC is more of an informational code, so if there are any other codes set, diagnose them first. If there are no other codes, inspect for vacuum leaks, restrictions, and damage. If there are no symptoms other than the DTC itself, just clear the code and see whether it returns

I have found most times that the throttle body has dirt or sludge build up and removing it and giving it a good cleaning may help it ...jazzmaster..

Dealer reccomended fuel injection system cleaning, would that cause the DTC and would that include cleaning the throttle body? Should they also check for the other reasons for trouble code at the same time?

yeah, it should includ cleaning out the throttle body as well, I would make a point of pointing that out so that it is done ,a fuel injection cleaning will clean it out (throttlebody) mostly but you want to get right at the throttlebody with a spray ,.

that should be included as this is usally a 3 step system cleaning .

1.hooking up to the fuel injection system and power flushing/cleaning the fuel system including the intake and fuel injectors

2.cleaning out the throttlebody by spraying the throttle body

3.additive to the fuel tank

yes, it would be good to check the pcv system and check it for vacuum leaks as well ..jazzmaster...

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.DianeDallas, TX

Ask a GMC Mechanic

Get a Professional Answer. 100% Satisfaction Guaranteed.

59 GMC Mechanics are Online Now

Type Your GMC Question Here...

characters left:

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.